The present invention relates to a system for and a method of determining a tentative master of a radio conference system in case of bringing an unspecified number of radio terminals to arbitrary places, determining a tentative master thereof, temporally constituting a network by means of radio using the tentative master as a center, and conducting communication. Conventionally, as this kind of a system for determining a tentative master, there is a system disclosed in JP-A-245690/1991, for example.
FIG. 5 is a view showing the construction of the entirety of this conventional conference system between multi-points. Multi-points control units (referred to as MCUs, hereinafter) 50-52 are arranged at each position, respectively, and have jurisdiction over communication terminals within each of control areas 80-82 and conduct entire control of a conference. For example, the MCU 50 has jurisdiction over the communication terminal 40 indicated as "A", the MCU 51 has jurisdiction over the communication terminals 41-43 indicated as "B"-"D", and, the MCU 52 has jurisdiction over the communication terminals 44 and 45 indicated as "E" and "F" Communication circuits 60-65 are connecting circuits for connecting finally determined optimum MCUs to each of the terminals 40-45. Communication circuits 70 and 71 are connecting circuits which are used when a notice from the terminal 40 of the opening of the conference is issued to the MCU 51 by way of the MCU 50. Each of the MCUs has a terminal control table (kinds of the circuit, fee information and so forth).
The system shown in FIG. 5 operates as follows:
At first, in order to open a multi-points conference between the terminal 40 and other terminals 41-45, the circuit 70 is connected to the MCU 50 over which the terminal 40 has jurisdiction, and a demand for opening the conference is transmitted to the MCU 50. For determining an optimum MCU for controlling the said conference, the terminal control table is referred to by the MCU 50 that has received the demand, and the MCU 50 determines whether or not only its terminal control table has enough information. If the terminal control table has enough information, the optimum MCU is determined based on the information, the circuit is connected to the optimum MCU. Here, if the MCU 51 is selected, the circuit 71 becomes to be connected to the MCU 50. In addition, based on the information for the determination, the sum total of fees is calculated and obtained, for example, in case of assuming that the terminals are connected to each other with each MCU placed at a center. Also, if the information is not enough for the sole determination by the MCU 50, the MCU 50 conducts communication with other MCUs 51 and 52 and determines the optimum MCU based on information obtained from each of the MCUs 51 and 52.
After the optimum MCU 51 is determined in this manner, the demand for the opening is transmitted to the MCU 51. And then, after the connections between MCUs are cut and a notice of the opening from the MCU 51 is issued to the terminal 40, the circuit 70 is cut. Thereafter, the circuits 60-65 are connected between the MCU 51 and each of the terminals 40-45, and the conference is held in an optimum connecting form.
As mentioned above, the optimum MCU is determined based on the information of the terminal control table which is stored in the MCU, using information of the terminal control tables of other MCUs also if necessary.
However, although, in this prior art, the MCUs are needed in addition to the terminals for determining the optimum MCU and setting communication paths, the MCUs do not always exist in case of bringing unspecified radio terminals to arbitrary places.
Also, since the MCUs have the terminal control table and the terminals do not have the terminal control tables, communication of the terminal information cannot be conducted by only the terminals, and accordingly, the optimum MCU (which is a tentative master in the present invention) cannot be determined by only the terminals.